The invention concerns a device to sand or polish floors or surfaces which incorporates a motor-driven sanding or polishing disc that rests during operation on the floor or floor surface in order to treat that surface and whereby a handle element is mounted on the housing to guide the device across the surface.
Such devices to sand or polish floors or surfaces are primarily used, for example, to treat wood or cork floors, but can also be used to treat other types of floor sub-surfaces. In the process, the surface of the floor is so treated by the device, that the surface is smoothed by sanding using a rotating disc or can also have a gloss texture imparted by polishing. Chemicals can also be sanded-in or polished-in during treatment of the floor. The devices used for sanding or polishing contain a motor drive which, for example, could be an electric motor. This motor causes rotation of a sanding or polishing disc which rotates on the surface of the floor while the device operates and whereby the rotating sanding or polishing disc can be guided across the surface to be treated by a standing person using the handle. The pressure required for sanding or polishing the surface to be treated is provided during operation of the device by the device's own weight.
A basic disadvantage of such a sanding or polishing device constructed in accordance with the currently known state of technology consists particularly in the existence of a strong sideward force during the operation of the machine, making controlled sanding or polishing only possible by the operator's use of force. The machine always tries to slide to the side. In addition, there also is the resulting disadvantage that, because of dynamic forces, the circumference area of the sanding or polishing disc always tries to penetrate into the floor or surface, thereby representing a severe impediment when treating a soft floor, like wood or cork floors. The known sanding and polishing device, after it has been placed in operation, always tends to wander from the starting position without the operator having exerted any influence at all. In order to counter this movement, the operator is required to exert much force and use skill in order to make possible a concentrated, controlled sanding or polishing of the surface. An additional disadvantage of this known device is the high consumption of sanding material because of the sideward force.
It is therefore an object of this invention to further develop beyond the stated stage of technology a device to sand or polish a floor or surface which, on the one hand, manifests controlled guiding stability and, on the other hand, conserves the use of sanding or polishing material during operation of the device. Another object is to provide a simple way of achieving the counter-rotation of the discs, and also of starting/stopping the rotation.